Innovative new panels could extend solar reach

Extreme Energetics' solar panels use transistors developed at Oregon State University (Photo:Xtreme Energetics)

A transistor technology developed at Oregon State University could literally change the face of building. Solar panels that use the technology could be light, cheap and attractive enough to grace façades.

Colin Williams, CEO of Xtreme Energetics, based in Livermore, Calif., realized he needed better transistors for solar panels his company was developing. A Web search turned up the transparent transistors developed at Oregon State and licensed to Hewlett-Packard.

“They had, by far, the best technology,” Williams said. “HP has a tremendous reputation for high-quality manufacturing and process control, and OSU has very high standards in doing cutting-edge research in this field.”

Researchers hadn’t imagined that the transistors would find their way into solar panels. “We were just trying to create something brand new,” said Douglas Keszler, distinguished professor of chemistry at OSU. “It didn’t come across our minds immediately.”

The obvious use of transparent transistors was in consumer electronics, Keszler said. The technology could be incorporated into liquid-crystal-display screens and even automobile windows.

“The first generation of applications related to displays,” Keszler said, “making a better LCD panel for a home or network PC.”

Williams realized his company could use the technology in a less-demanding way: to follow the sun.

Currently, the most efficient solar arrays had used a tracking mechanism to turn the panels toward the sun, he said.

The new technology puts the tracking device inside the panels themselves, Williams said. The transparent transistors don’t block light, allowing a more efficient conversion of sunlight into electricity – more than twice as efficient, he said.

Lenses focus the sunlight on a small focal point, and layers of different materials convert energy from different pieces of the spectrum. Without a mechanical tracking system, the panels are also lighter, thinner and easier to incorporate into buildings, he said.

The visual effect is also different. Viewed from an angle, the Xtreme Energetics panels allow color to come through from behind the array of inch-wide collectors. “That gives you the opportunity to put artistic coloring behind the panel,” Williams said.

“You can build it into the building, so the appearance of the building will change from colored to mirror to colored,” depending on the viewer’s angle.

Solar technology has improved, said Bruce Brown, principal with GBD Architects, but designers have some limitations in how the panels are used. “If you do panels at an angle, which is most efficient, then wind becomes an issue.

“They have to be bolted or ballasted,” Brown said. “And if a big wind comes along, they could just sail away.”

Brown hasn’t seen the Xtreme Energetics prototype, which Williams expects to have ready in the next few months. But he said he’d welcome lighter, more efficient panels.

“Any panel that is more easily integrated into the structure or skin of the building is a positive,” Brown said. “Everybody wants to see the efficiency go up, up, up, which means the cost will go down, down, down.
“The payback period will be less and the panels will become much more common.”

Oregon State’s Keszler envisions a second generation of applications of the technology in printed transistors that could be incorporated into building façades. “The long-term goal is to move beyond (silicon) wafers and to go to larger areas.

“Usually, when people think about printing electronics, they think of compromised performance,” he said. “We’re looking to improve performance, and looking at the next-generation technologies in the context of being able to do that.”